Lace web separation



April 26, 1949. J. SPALDING 2,468,310

LACE WEB SEPARATION Filed May 15, 1947 3 Sheets-Sheet l 10 v 12 J5 /I| oS e 1" W a INVENTOR Jo/zn/ dismal/g9 BY ATTORNEYS April 26, 1949.sPALDlNG 2,468,310

LACE WEB SEPARATION I Filed May 15, 1947 3 Shets-Sheet 2 ATTORNEYS April26, 1949. J. SPALDING 2,468,310

LACELWEB SEPARATION Filed May 15,1947 9 5 Sheets-Shet s UMW -N-MATTORNEY Patented Apr. 26, 1949 UNITED STATES PATENT OFFICE LACE WEBSEPARATION John Spalding, Stratford, Conn.

Application May 15, 1947, Serial No. 748,365

14 Claims. (Cl. 28-73) This invention relates to processes and apparatusfor separating lace webs into strips of lace. In my Patent 1,665,230there were disclosed webs of the general type referred to, and in whicha plurality of lace strips are held together by connecting threads whichare of a composition different from that of the threads forming thelace, and of such a character that they can be dissolved out by the useof a suitable solvent. For instance, if such threads be of celluloseacetate they can be dissolved by the use of acetone or other suitablesolvents, and the strips thus freed from each other. The dissolving ofthe connecting threads can be effected in an apparatus such as thatdisclosed in my Patent 1,865,218, but this requires saturating the rollwith solvent and the later removal of the solvent. Instead of dissolvingthe connecting threads they may be of such a composition that whenheated they can be easily broken into short sections. For instance theymay be made from vinyl chloride vinyl acetate mixtures, or the like,such as are commonly sold under the trade-name Vinyon, or the threadsmay be of other synthetic composition which has low tensile strengthwhen heated. By heating the connecting threads while they are undertension, they will contract endwise and break, thus freeing the lacestrips from each other. Webs of such character, and a process andapparatus for separating them by breaking the connecting threads, aredisclosed in my Patent 2,346,195. Such a process is advantageous in thatno solvent is required, and a dry web may be progressively passedthrough a heating and thread-breaking apparatus; but in the formillustrated in said patent it is necessary to employ a plurality ofthread heating and breaking units, and to provide for the adjustment ofsuch units toward and from each other in accordance with the width ofthe lace strips so as to operate therebetween.

My present invention involves a new and improved process and apparatusfor treating webs such as those disclosed in the last mentioned patent,to effect the heating and breaking of the connecting threads and theremoval of residual portions of the broken threads, but without the needfor the large number of of separate and adjustable heating andthread-breaking elements there disclosed. I have now discovered that theheating and breaking of the threads may be effected by merely passingthe web through or over a heating unit while so holding the web that thelace strips cannot stretch or move laterally,

or pull together during the heating step. Thus the breaking is effectedby the mere contraction or shortening of the threads, as a result of theheating and the great reduction in tensile strength of the threads.

As an important feature of the invention the web is passed between apair of rolls which heat the connecting threads and at the same timepinch the web and prevent edge of the lace strips from pulling towardeach other. Thus the contracting or shortening of the threads causesthem to break.

As a further important feature of the invention, a sheet is pressedagainst the web and passes with it over the heating means so as todirectly contact with the connecting threads while heat is beingapplied.

As a further feature, at least one of the sheets is provided with acoating of a thermoplastic material which has little or no adhesion tothe threads of the lace itself, under the conditions under which it isemployed, but the softened and broken connecting threads will adherethereto, so that upon separating the coated sheet from the lace, it willcarry with it and remove from the lace the residual portions of thebroken threads, and leave the lace strips completely freed from eachother and ready for packaging.

In carrying out my invention, the steps of holding the strips againstlateral movement, the heating of the connecting threads to cause them tobreak, and the removal of broken threads may be effected byprogressively bringing the web and the coated sheet together, passingthem over and pressing them against a transversely extending heatingelement such as a roller, and then progressively separating the sheetand the separated lace strips to leave the residual portions of thethreads on the sheet.

Mechanism may be employed for slightly stretching the web laterally asit passes onto the heating unit, but ordinarily this is not necessary ifthe web be smoothed out before it is delivered with the sheet andpressed onto the heating element sufiiciently firmly so that anysubstantial lateral movement or lateral stretching of the lace isprevented. By making the threads of a suitable composition, they willbreak with only a small reduction in, length, due to the great loweringof the tensile strength as a result of the heating.

If the threads be for instance of a proper synthetic composition,suflicient contraction and decrease in tensile strength will be effectedto cause breaking with very little heating, which may be to atemperature somewhat above C.

thereto.

I have referred to the use of a sheet, but it is preferable to use twosheets with the web pinched between them at the instant of heating.

The sheet or sheets may be made of any material of sulficient strengthand flexibility, such as paper, cellophane, cloth, etc., and the coatingmay be of a composition which becomes somewhat tacky in the temperaturerange in which the threads lose their tensile strength. The temperatureto which the threads are heated may be varied in accordance with thecharacter or composition of the connecting threads, but should besufficiently high to give a rapid heat transfer through the sheet orsheets to the threads to be broken, and while the sheet and/ or Web isin contact with the heater for only a very short time.

Various different coating compositions may be used on the sheet providedthey are such as'will, when heated, cause the broken threads to adhere Acomposition which has been found suitable is similar to that of thethread to be broken. If vinyl chloracetate threads be used as connectingthreads in the web, the coating may be vinyl chloracetate dissolved indichlorethylene, spread on one surface of the sheet of paper and thendried.

The sheet or sheets may be of the same length as the web and be unrolledfrom one roll, fed along with the web over the heating element, androlled up on another roll; or they may be endless, and repeatedly-passedover the heater with the 'web and then around idler rollers.

The heating and pressure applying unit may be a pair of rollers, asingle roller, or a stationary member presenting a curved surface overwhich the web and sheet are moved. I

'Merely as examples of lace webs which may be separated by my improvedprocess, and of apparatus suitable for carrying out the process, certainforms are shown in the accompanying drawings. In these drawings:

Fig. 1 is a greatly enlarged view of a portion of a web showing athermoplastic connecting thread between adjacent edges of two lacestrips.

"Fig. 2 is a view similar to Fig. 1, but showing a form in which thethermoplastic thread is straight, and rover or drop out threads areemployed.

Fig. 3 is a side view showing diagrammatically one form of apparatuswhich may be employed.

Fig. 4 is a view similar to Fig. 3, but showing an alternativearrangement,

Fig. 5 is a top plan view of apparatus showing some but not all of theparts of the apparatus diagrammatically shown in Fig. 4, and on a largerscale and Figs. 6 and '7 are side views showing diagrammatically twoother forms of apparatus which may be employed.

Inthe somewhat diagrammatic showing in Fig. 1, of a portion of a laceweb on a very greatly enlarged scale, there is provided a thermoplasticthread A which passes around threads B and C of two lace strips so as tohold said strips together, but slightly spaced from each other. It willbe noted that by destroying the thread A the lace strips will be freedfrom each other, and it will also be noted that the connecting thread Apasses freely through holes in the edges of the lace strips, and whichare sufficiently large so that there is no binding action even if thethread contracts in length so as't'o be of much larger diameter. If .thethread A be broken at most,

if not all of the transverse passes thereof, the

r, heated rolls H.

residual portions of the thread are easily removable from the lacestrips.

In the lace web shown in Fig. 2, the thermoplastic connecting thread Ais substantially straight, and passes through loops of rover threads Dand E which are also looped through the lace so that they are freed fromthe lace by the breaking of the thread A. Thus the rover threads'willfall out or can be lifted off the lace.

In the apparatus diagrammatically illustrated in Fig. 3, the web W istaken from any suitable source, and between a pair of feed rolls I0.Care should be taken that the web is smoothed out before entering thefeed rolls, and if desired any suitable form of guiding or lateralstretching means may be employed to make sure that there is nosubstantial amount of slack in the connecting threads, or this may bedone by hand.

The lace web passes in fiat, smooth form from these rolls to a pair ofrolls ll, one or both of which may be heated. As the web passes betweenthese rolls it is engaged on its upper and lower surfaces by sheets l2which are of a width at least as great as that of the web. The sheetsmay be taken from supply rolls l3 which may have brake mechanism orfrictional resistance to rotation, so that the sheets will be fiat,smooth, and if desired taut, and will lie on opposite sides of the webas the latter passes between the The sheets l2 separate from the web asthe latter leaves the heated rolls, and may be wound up on rolls M. Theweb is pulled between the heated rolls by draw rolls l5, and at the samespeed as the sheets are wound on rolls It. The drive for the rolls 14may have a slip friction drive so that the speed of rotation maydecrease as the diameter increases.

As previously explained, the temperature of the heated rolls l I is suchas will cause the con- I necting threads'between adjacent lace strips tocontract and break, and as'the sheets l2 have a coating of thermoplasticmaterial which will cause the residual portions of the broken threads toadhere thereto, said sheets will carry them away from the separated lacestrips. The separated strips S delivered by the draw rolls l5 may bepassed over a roller 5, and accumulate in a suitable receptacle, or maybe progressively and separately wound up or otherwise disposed of.

In Fig. 4 there is shown a modified form in which the coated sheets l2instead of being taken from one roll and wound up on another, areendless, and pass around pairs of idler rolls l1 and I8.

I have not illustrated details of any driving mechanism for any of therolls, but it will be understood that they may be driven by any suit-'able means, and at the proper relative speeds. The heated rolls may beof conventional type; that is hollow, and provided with means for thecirculation of steam or hot water through them, as for instance frompipes 20, or they may be heated in any other suitable manner. The laceweb will be gripped between the rolls, and the gripping may be due tothe weight of the upper roll, or conventional means may be employed forpressing them together. As a result of the gripping or pinching actionof the rolls l I, the separate strips are prevented from stretchinglaterally under the tension created in pulling them endwise, or thetension of the connecting threads as they are heated andcont'ract inlength before they break.

The residualportions of the connecting threads and releasing of the weband sheet.

adhere to the coating on one or both of the sheets, and are carried awayfrom the separated strips by the sheets. They may remain permanentlyattached to the coatings on the sheets, particularly if such coatingsare of a composition somewhat similar to that of the threads. As thethreads are of small diameter and there may be only a few of suchthreads in a web composed of wide lace strips, the sheets may be usedrepeatedly, and the residual portions accumulate on the coatings. Whensuch accumulation becomes excessive, the coatings with such residualthread portions, may be dissolved off from the sheet, and new coatingsapplied.

In the form shown there are two of the coated sheets, one on each sideof the web. In some cases, particularly where the lace is very thin, oris of extremely open mesh, it is preferable to have only one of thesheets coated, so that the coatings cannot directly contact throughopenings in the lace, with the possibility of their adhering to eachother. As previously noted, in some cases only one sheet need beemployed.

In the constructions illustrated the heating elements are rolls. It willbe obvious that where two rolls are used only one need be heated,particularly if only one coated sheet is employed. Substantially thesame effect is obtained if the coated sheet or sheets and the lace webpass over and along a portion of a curved surface of a stationary ornon-rotating heating element. In that case the web and sheets slide overthe heating element instead of moving with the surface of the heatedelement.

In Fig. 6 I have shown such an apparatus, and which may be similar tothose shown in Figs. 3 and 4 in all respects, except that the upperheating roll II is omitted and the lower heating roll ll replaced by aheater Ila, which has an upwardly facing curved surface over which theweb W may slide. Pairs of feed rollers 2| for the coated sheet l2" arepositioned opposite the ends of said heater and the heating fluid may bedelivered at the upper part through a pipe and withdrawn from the lowerpart through pipes 20".

In some cases the heated elements may be flat plates, and the web andsheets advance step by step between said elements. In this case theelements are intermittently moved toward and from each other to causealternate compressing This has the advantage of insuring uniformapplication of heat across the entire width of the sheet, and permitsthe use of a lower temperature for a longer time than is the case wherethe sheets merely pass between two rolls which apply the heat along onlynarrow areas, and only for an instant.

In Fig. 7 I have shown such an apparatus, which is similar to that shownin Fig. 6 except that two flat heaters II b are used, these havingparallel surfaces. At least one of these heaters may be moved toward andfrom the other to grip and release the web, as indicated by the arrows,and the rollers are rotated intermittently to advance the coated sheetl2" only when the heaters are separated.

In some cases the web may be moved intermittently over a flat platen,and between successive advancing movements a roller may be caused tomove over the platen and across the sheet, either or both the platen androller being heated. In all cases the openings in the lace, and throughwhich the connecting thread passes,

should be enough larger than the diameter of the connecting thread as toavoid any liability of the thread portions being held in the lace afterthe diameter of the threads has increased, upon endwise contraction andbreaking.

Having thus described by invention, what I claim as new and desire tosecure by Letters Patent is:

1. The process of separating into strips a lace web of the type in whichlace strips are connected edge to edge by threads of a compositionhaving low tensile strength when heated, said process including thesteps of applying to the web a sheet having a coating of adhesivematerial, and heating the web to cause contracting and breaking of saidconnecting threads and the adhering of the residual portions of thebroken threads to said sheet.

2. The process of separating into strips a lace web of the type in whichlace strips are connected by threads of different composition from thatof the threads of the lace, and having low tensile strength when heated,said process including pressing the web against a sheet having anadhesive coating, and heating the web to cause said threads to contractand break and adhere to said sheet.

3. The process of separating into strips a lace web of the type in whichlace strips are connected 'by threads of a composition having lowtensile strength when heated, said process including pressing the webbetween a pair of sheets, at least one of which has an adhesive coating,and heating said web to contract and break said connecting threads.

4. The process of separating into strips a lace web of the type in whichlace strips are connected by transverse threads which shorten and. havelow tensile strength when heated, said process including passing the weband a sheet having an adhesive coating between a pair of rolls, at leastone of which is heated, thereby to contract and break said connectingthreads, and separating said sheet from said strips, and with theresidual portions of said connecting threads adhering to said sheet.

5. The process of separating into strips a lace web of the type in whichlace strips are connected by transverse threads of a composition havinglow tensile strength when heated, said process including the steps ofapplying to the web a sheet having a coating of adhesive material,holding the web against lateral contracting, and heating the web tocause contracting and breaking of said connecting threads and theadhering of the residual portions of the broken threads to said sheet.

6. The process of separating into strips a lace web of the type in whichlace strips are connected by transverse threads of different compositionfrom that of the threads of the lace, and having low tensile strengthwhen heated, said process including the steps of applying a sheet havingadhesive coating to hold the web against lateral contracting, andapplying heat to the surface of the web to contract and break saidthreads.

7. The process of separating into strips a lace web of the type in whichlace strips formed of cotton threads are connected by transverse threadsformed of nitrogenous synthetic material having low tensile strengthwhen heated, said process including the steps of applying a sheet havingadhesive coating to hold the web against lateral contracting, andapplying heat to the surface of the web to contract and break saidthreads.

8. The process of separating into strips a lace web of the type in whichlace strips are connected by transversethreads of :a composition havinglow tensile strength when heated-said process includingpassing'the Webandaa' sheet having an adhesive coating between aipair of heated rollsto prevent lateral contraction of the web while heating the web toefiect contractionand breaking of the connecting threads.

'9. The process of separating into strips a lace web of the type inwhich lace strips are connected by transverse threads having low tensilestrength when heated, said process including the steps of applying tothe web a sheet having a coating of adhesive material, andpassin-g theWeb and sheet between a pair ofheated rolls thereby to prevent lateralcontracting of the web while heating the same to cause contracting andbreaking of the connecting threads.

'10. The process of separating into strips a lace web of the type inwhich lace strips are connected by transverse threads having low tensilestrength when heated, said process including thesteps of pressing theweb between a pair of sheets, at least one of which has an adhesivecoating, to hold said sheets against lateralmovement, and simultaneouslyheating the web and sheets to contract and break the connecting threads.

11. The process of separating into strips a lace web of the type inwhich lace strips are connected by transverse threads of a compositionhaving low tensile strength when heated, I said process including thesteps 'of pressing the web between a pair of sheets, at least one ofwhich has an adhesive coating, simultaneously heating the web and sheetsto contract and break the connecting threads, and separating said sheetswith the residual portions of said threads from the separated strips.

12. The process of separating into strips a lace web of the type inwhich lace strips are connected by transverse threads of a'co'mpositionhaving low tensile strength when heated,- said process including thesteps :of pressing the web between a pair ofvsheets, at least one ofwhich has a coating of acomposition similar to that of said transversethreads, simultaneously heating the web and sheets to contract and breakthe conne'cting threads, and separating said sheets with the residualportions of said threads from-the separated strips.

13. Thep-rocess of separating into strips a lace web of the type inwhich lace strips are connected edge to 'edge by threads of acomposition having low tensile strength when heated, said processincluding the steps of applyingto the web a sheet having a coating of acomposition similar to that of the connecting threads, and heating theweb to cause contracting and breaking of said connecting threads and theadhering of the residual pertions of the broken threads to said sheet.

14. The proc'ess of separating into strips a lace web of the type inwhich lacestrips are connected by threads of a composition having lowtensile strength when heated, said process including pressing the webbetween a pair of sheets to prevent contraction, at least one of whichsheetshas a coating of a composition similar to that oithe connectingthreads, and heating said web to contract and break said connectingthreads.

JOHN SPALDING.

REFERENCES CITED The following references areof record in'the fileorthispatent:

UNITED STATES PATENTS Number Name Date 2,297-;881 Fuller 'Oct. 6, 19422,346,195 Spalding Apr. 11, 1944

